Miles Per Gallon

[Guinnessecco]

What is the fuel consumption for a 1988 American Clipper with the 440 engine at about 60 mph on level ground.  With the price of gasoline where it is, I was just wondering what a trip is going to cost me, and I have not had the RV long enough to make my own calculations.

[mollerus]

I presume you mean a 1978 Clipper.  I get about 7 to 71/2 miles per gallon and I seldom go over 55 mph.  We push a heavy load with a big engine so gas "economy" is impossible.  The enjoyment and convenience of using my Clipper more than makes up for the cost of operating it.  
Bob Mollerus

[Horst]

It depends on how well tuned you rengine is, and how heavy you are, head versus tail wind, etc.
You will likely get somewhere between 6mpg and maybe 8mpg at 55mph. At 60, your mileage begins to drop off noticeably - you're better of at 55.

Had a friend get 4 mpg with his Clipper towing his boat into a fierce headwind - ouch!

[Guinnessecco]

My wife really likes to drive at 65 MPH.  I like 55 MPH myself.  So, just how bad is the mileage at 65 MPH?  I have tried to get her to drive slower.  Maybe it is wishful thinking, but if I can tell her how bad the mileage is at 65 MPH, she might slow up  

[Horst]

Here's my "guesstimate" - based on personal experience, and that of others.
I'll wager you get  1.5 miles per gallon more at 55mph than at 65mph.
Simple math - 50gal gas tank = 75 miles more distance per tank full. So you save about 10+gals, or $20 or so per tank by driving 55mph. Adds up pretty quick.

More importantly - I'd MUCH rather be doing 55mph if I  had to make emergency moves, or suffered a blowout - than be doing 65. Just have a look at stopping distance charts , and look at the difference between 55 and 65:

The difference will  surprise you.
A car going 55 takes about 225 feet to stop (reation distance plus stopping distance) - at 65 this goes up to about 320ft.
In a Clipper, both these figures go up substantially, especially the stopping at 65mph. Those Dodge guys made two blunders when engineering the Dodge Van - carburators and brakes - other than that they are pretty well made.

[atvclipper]

1977 w/440 (stock) towing 900#
57-62mph
I live in Central Oregon where the elevations range from 3000 to 6000 feet. We have hundreds of miles of very flat roads and just as much very mountainous. My worst milage was 7.7mpg going over three 5000 foot passes on the way to Sumpter. My best is 8.1mpg.